I have a 2001 MX5 MkII that had been flooded but not as far as ECU box. Removed seats and changed carpets. Red Airbag warning light comes on dashboard.Removed Drivers seat but no wire connected to it. Wire under carpet but not connected. Stripped drivers seat down to foam but no seat sensor or seat belt sensor.. looks as if there never has been.Before I remove and strip passenger seat which is connected to wire under seat what else should I check? Thanks

Dashboard lights – I would remove the rheostat. Mine came without one and when I fitted one the lights became about 20% dimmer even on the max setting. This can be done by connecting the 2 wires into the rheostat together (if there are only 2 wires..) as it is basically just a variable resistor and some cars came without them and the bulbs do not need it. Eddie is right about the bulbs silvering/smoking themselves as they age due to the gas leaking out of them. Another thought is you can probably get LED lights that are 2-3 times brighter but they may not work if you try to turn down the rheostat as they will have a minimum operating voltage unlike good old incandescent/filament bulbs. LED folk will say they will last longer ... in my experience the LED may but the driver electronics behind it fails so in reality there maybe little gain.

For airbag issues go Google “miata nb airbag light site:forum.miata.net” .. or just Google “Miata air bag light NB”. US/Miata cars may have different controllers etc but generally they are the same behind some odd Euro/Japan wiring differences. Reading that you should get a flashing air bag light sequence which normally happens when you turn the ignition on. The USA government mandated that but on Mk1 UK cars you have to go the diagnostic plug under the bonnet to get those codes for the engine so I am guessing the ABS system is similar. Note Miatas have a key to deactivate the passenger airbag so ignore that part.